Funding for this research was provided by:
Fundação para a Ciência e a Tecnologia (UID/AGR/04033/2013, PD/BD/113617/2015, PD/00122/2012, CEECIND/00447/2017)
Text and Data Mining valid from 2019-04-17
Received: 7 December 2018
Accepted: 15 March 2019
First Online: 17 April 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.